This invention is directed to a liquid containment/diversion dike and, in particular a liquid-fillable containment/diversion dike for flood control or liquid containment, bladder elements for use in the dike and a method for construction of a liquid containment/diversion dike.
Many systems have been employed for controlling the spread of flood waters or fluid spills. One of the most common means for containing or diverting a flow of liquid is sandbagging wherein bags are filled with sand and piled to form a dike. Sandbagging to divert liquid flow has certain disadvantages including the cost of producing the sandbags and the difficulty in removing the barrier of sand bags when it is no longer required. SUMMARY OF THE INVENTION
A liquid-fillable liquid containment/diversion dike has been invented which can be used to contain or divert a flow of liquid such as a flood or a liquid chemical spill. The dike is easily transported and is tillable on site. When the dike is no longer required, it can be emptied of the liquid it contains and then transported to the next site where it is required. The dike is resistant to failure due to puncture because of a multiple bladder arrangement.
Thus, in accordance with a broad aspect of the present invention, there is provided a dike section having a length and comprising a first elongate bladder formed of a flexible material to contain a liquid and a second elongate bladder formed of a flexible material to contain a liquid, the first elongate bladder and the second elongate bladder extending in side-by-side relation at least along a length of the dike, at least one wall dividing the first elongate bladder from the second elongate bladder, the wall formed to prevent any flow of liquid between the first elongate bladder and the second elongate bladder.
The dike section can have further bladders extending along the length thereof provided that at each cross-section along the long axis of the dike section there are at least two bladders extending in side-by-side relation. The dike section includes at least one wall between at least two bladders, the wall being selected such that no fluid flow is permitted between the bladders. However, where the dike section includes more than two bladders extending in side-by-side relation, some of the walls between the bladders can have formed therein perforations to permit water flow therethrough in order to facilitate filling of the dike section with liquid.
Preferably, at least some of the bladders in a dike section are secured together. The bladders can be secured together in any suitable way. In one embodiment, the walls of some of the bladders are formed integrally with each other. In another embodiment, the bladders are formed separately and are connected by any suitable means such as, for example, heat welds or fasteners such as rivets, belts or rope extending between the bladders or between apertures formed on the bladders.
The bladders are formed of any material which is flexible and which can contain water (i.e., watertight). As an example, the bladders can be formed of woven polyester or nylon fabric coated on one or both sides with urethane or vinyl. Preferably, the bladders are formed of 17 to 50 ounce woven polyester coated with vinyl on both sides. Any seams are sealed as by heat welding, adhesives or sewing to effect a liquid-tight seal.
Sealable ports are provided in each separate bladder to provide for access to the interior of the bladder for filling. Preferably, a one-way valve is provided at each port for connection to an injection nozzle. In a preferred embodiment, a header device is provided having a plurality of connectors for simultaneous connection to a plurality of bladder valves. Such a header device provides that more than one bladder can be filled simultaneously. Preferably, all valves are positioned on the side wall of the bladder or on the end wall of the bladder proximal to a side of the bladder to facilitate filling of the bladder without collapse. To prevent overfilling, preferably a check valve is provided in a wall of the bladder. In one embodiment, a pressure transducer is positioned in communication with the interior of at least some of the bladders of the dike section so that an alarm will sound if the pressure in a bladder falls below a predetermined level.
To form a dike, one or more dike sections are positioned on the ground in substantially the final selected site of the dike and the bladders are filled with a liquid, for example, water from a potable water supply or surface water. A seal is effected between the dike section and the ground by the weight of liquid forcing the walls of the bladders into close contact with the ground and each other to prevent a passage of liquid therepast. Where more than one section is required to form a dike, the dike sections are positioned in end-to-end contact such that they seal against one another. The dike sections can be formed with ends of any shape provided they are formed to fit together with other dike sections to form a seal therebetween. Thus, the dike sections can be blunt, slanted or irregular at their ends. In one embodiment, the individual bladders of the dike sections are formed to be connected to the bladders of the abutting dike section.
In one embodiment, the dike section includes a pyramidal configuration of elongate bladders. As an example, there is a base layer of bladders positioned to extend in side-by-side relation. On this base layer are positioned a second layer of bladders. The number of bladders in the second layer is less than the number of bladders in the base layer. If possible, a third and further layers of bladders are positioned on the second layer. The walls of the bladders can be formed fully or partially integral with each other. In one embodiment, the dike section is formed from a plurality of elongate dike bladders which are fully or partially separable.
It has been found that the operation of the dike section can be enhanced by preventing the water from seeping between the bladders. Thus, in one embodiment, a sheet of material can be partially or fully wrapped about the dike section at the intersection of abutting dike sections or along the length of a dike section. In addition, or alternately, a sheet of material is positioned over the containment side of the dike section to extend a selected distance over the ground surface away from the dike section. The sheet of material is preferably liquid-tight.
In accordance with another broad aspect of the present invention, there is provided an elongate dike bladder comprising: a tube closed at its ends and having a wall and a long axis between the ends, the tube formed to be flexible and watertight, and at least one port for access to the interior of the bladder.
In one embodiment, each elongate dike bladder is formed as a tube of flexible, watertight material with a membrane extending across the interior of the tube parallel to the long axis thereof. Preferably, the membrane extends substantially across the diameter of the tube. The membrane can be solid or perforated. A bladder is primarily intended to be used in combination with other bladders for liquid containment or diversion. However, a bladder can be used alone for containment or diversion of a flow of liquid depending on the size of the flow of liquid and the size of the bladder. In such a situation, however, the bladder to be used should be one in which the membrane is solid and does not permit fluid flow through the membrane so that a puncture along the bladder will not result in a complete loss of water pressure in the bladder.
According to another feature of the present invention, the bladder is formed as tube and the open ends are heat sealed or welded. To provide additional strength and integrity to the bladder ends, at least one of the ends is folded back on the bladder and maintained in this configuration by an end reinforcing sleeve. Thus, the ends do not independently withstand the pressure of the liquid within the bladder but instead are reinforced beneath the sleeve. Such a bladder is producible at low costs since a tube of watertight material can be used and cut into any suitable length and heat sealed or welded. Low cost welding procedures have been found to be particularly appropriate and cost efficient to close off the ends of the tubes.